1. Field of the Invention
The present invention relates to an elastic shaft coupling of the type comprising two identical hubs and a hollow shaft.
2. Description of the Related Art
On the basis of the cardanic principle, elastic shaft couplings of this type, which are fitted with elastic ring elements (resilient links), permit relatively large parallel and angular misalignments as well as axial displacements while transmitting torque. The hollow shaft can be made of one piece or, for reasons of assembly, it can be made up of separate parts. In particular, the same parts--i.e. the two hubs and the hollow shaft--can be combined with one another in various ways. The two hubs may be located inside the hollow shaft in order to achieve the shortest possible overall length; alteratively, one or both hubs can be fitted in such a way that they project beyond the end or ends of the hollow shaft, thus increasing the overall length of the coupling. In both cases the cardanic principle is retained.
In a known elastic coupling of the above-mentioned type (Thomas coupling, Type AM, as shown in FIG. 2.8-34 on p. 30 of the "Kupplungs-Atlas" [Handbook of Couplings], 4th edition, by August Schalitz), there is no danger of slip occurring should one of the elastic ring elements fracture because the ring element is located in a gap between the hub flanges and the flanges of the hollow shaft, which are arranged alongside each other. In addition, an elastic coupling is known from German "Auslegeschrift" DE-AS No. 21 00 05, which incorporates elastic links between two hubs and has an antislip mechanism consisting of spherical roller bearings which engage in cylindrical boreholes. However, in this known coupling the above-mentioned possibility of combining the hubs and shafts to vary the overall length does not exist.